Oh, come on, it’s not like North Korea is the only government that would declare the U.S. to be a terrorist nation. There’s also Cuba, Vietnam, Burkina Faso, Laos, Haiti, Venezuela, and Nicaragua, just to name a few. Not to mention (People’s Republic of) China too, given that they bombed a Chinese embassy in 1999. These are more than 3 governments.
If you have an argument against these nations considering the U.S. to be terrorist, then too bad. According to your own logic, these governments are also what decides terrorists.
Do you not like how these governments also legitimately decides what are and aren’t terrorists? Maybe you should recognize the flaw in your own logic, then.